Replicate a list to create a list-of-lists

Question

I am trying to create a list with the following (nested) structure:

l <- list()
for(i in seq(5)) l[[i]] <- list(a=NA,b=NA)
> str(l)
List of 5
 $ :Li         


        

Answer 1

You can use replicate:

l <- replicate(5, list(a=NA,b=NA), simplify=FALSE)